> ## Documentation Index
> Fetch the complete documentation index at: https://docs.apowerb.com/llms.txt
> Use this file to discover all available pages before exploring further.

# MCP

> Reaching Model Context Protocol servers, and registering your own.

Beyond its own Python tools, an agent can call tools served by a **Model Context Protocol**
server. The core supports two routes, and they solve different problems.

## Toolsets built into the portfolio

Two portfolio modules are MCP clients rather than plain functions:

| Module           | Server                       | Configuration                                                              |
| ---------------- | ---------------------------- | -------------------------------------------------------------------------- |
| `web_search_mcp` | Tavily, over streamable HTTP | `TAVILY_API_KEY`                                                           |
| `database_mcp`   | MCP Toolbox for Databases    | `MCP_TOOLBOX_URL` (default `http://localhost:5000`), `MCP_TOOLBOX_TOOLSET` |

Leave `MCP_TOOLBOX_TOOLSET` empty to load every tool the Toolbox exposes, or name one
toolset to load just that.

They are discovered by their name: `tool_manager` treats any `mcp_tool_set_*` attribute as
a **factory** and calls it when the agent is built.

<Note>
  The factory matters. A toolset instantiated once at import would capture the API key of
  that moment and keep using it after a rotation. Calling the factory per build means the
  connection is created with the key that is current.
</Note>

### MCP Toolbox for Databases

The Toolbox is a separate process, with its own binary and a `tools.yaml` describing the
databases it may reach. The core only needs to know where it listens.

| Variable          | Default                 | Description                                                                                                   |
| ----------------- | ----------------------- | ------------------------------------------------------------------------------------------------------------- |
| `TOOLBOX_DIR`     | —                       | Directory holding `tools.yaml` and the binary. Empty falls back to `RUNTIME_ROOT`, i.e. the working directory |
| `TOOLBOX_PORT`    | —                       | Port the Toolbox listens on                                                                                   |
| `MCP_TOOLBOX_URL` | `http://localhost:5000` | URL the agent connects to                                                                                     |

## Servers registered at runtime

Servers do not have to be baked into the portfolio. They can be stored and edited through
the API, which is what the interface uses:

| Method | Endpoint                           | Description                                         |
| ------ | ---------------------------------- | --------------------------------------------------- |
| GET    | `/api/mcp_configs`                 | List registered servers                             |
| POST   | `/api/mcp_configs`                 | Register one                                        |
| PUT    | `/api/mcp_configs/{mcp_config_id}` | Update one                                          |
| POST   | `/api/mcp_configs/reload`          | Re-read the configurations and rebuild the toolsets |

`reload` exists because a new server is useless until the toolsets are rebuilt — it saves
restarting the server to pick up a configuration change.

<Warning>
  An MCP server is code you do not control, invoked by a model. Its tool descriptions
  reach the agent's prompt, so a server you did not vet can influence what the agent
  decides to do. Register servers you trust, and prefer scoping a Toolbox to named
  toolsets over exposing every database it can see.
</Warning>


## Related topics

- [List Mcp Configs](/api-reference/tools/list-mcp-configs.md)
- [Update Mcp Config](/api-reference/tools/update-mcp-config.md)
- [Save Mcp Config](/api-reference/tools/save-mcp-config.md)
- [Reload Mcp Toolbox](/api-reference/tools/reload-mcp-toolbox.md)
- [Tools](/guides/tools.md)